Human Activities and Environment

Growth of human population, fast but unplanned industrialization and irresponsible behavior to environment are causing imbalances in the local, regional, national and global environment. These are causing not only local but global problems in the environment.

Increasing water, air and soil pollutions everywhere; destruction of forests, throwing away the industrial as well as radioactive wastes in oceans are such examples of human activities that are challenging the environment of the whole world.

Depletion of ozone layer, problem of wastes, global warming, climate change are some of the problems in the environment that are causing worry for the whole world. Here, we are going to study about the depletion of the ozone layer and disposal of wastes.

Ozone Layer and its Depletion

Ozone is a gas which is found around the earth as a thick layer. This gas is formed due to breaking up of oxygen molecules under the influence of solar energy. First the molecules of oxygen break into atomic form and then the atomic oxygen combines with the molecular oxygen to form ozone (O₃).

Ozone layer is the protective umbrella of the earth. When the concentration of Chlorofluorocarbons, aerosols, Carbon tetrachloride and Chlorine etc. increases in the atmosphere, they react with ozone leading to thinning of the ozone belt or making hole into it.

Ozone absorbs the ultraviolet radiations coming from the sun checking them against reaching to the earth. Following may be the bad impacts of Ultraviolet radiations reaching to the earth –

• Cataract in eyes
• Skin cancer
• Damage to DNA molecules causing genetic diseases
• Losses to fish and sea animals
• Damage to plants and trees

Following are the measures to check the depletion of the ozone layer –

• Checking the production and application of Chlorofluorocarbons
• Search of safe alternatives of Chlorofluorocarbons
• Checking the production and use of aerosols
• Search of suitable alternative to use in refrigerators other than aerosols

The whole world is worried about the loss to ozone layer. The main cause of the depletion of this layer is the artificially synthesized chemical called as Chlorofluorocarbons (CFCs). This chemical is used in aerosol sprays and coolants. The world level conference to control and check the ozone depleting substances was held under the banner of United Nations Environment Programme (UNEP) in 1986. India too is a signatory to this programme.

Waste

Now markets are flooded with new products and their consumption too has increased due to population explosion. We bring home different types of materials along with products we purchase from markets.

These materials constitute major part of wastes that we throw away out of our houses. This throw away culture is causing accumulation of waste here and there on the face of the earth. This is called as soil pollution or land pollution.

1. Different types of waste

Where ever the waste is thrown it occupies some place. It has weight and cause bad smell. Thus waste is substance or matter. We know that matter contains energy. Thus high amount of energy is thrown away locked inside waste.

Waste too is found in three states- solids, liquids and gases. Liquid wastes such as different types of chemicals, useless medicines, detergents, pesticides, oil, automobile wastes etc. spread on the soil surface and make it poisoned. Decomposition and burning of things on ground produce different gases that pollute the air.

• Harmful impacts of solid wastes

Following are the harmful impacts of accumulation of solid wastes-

(i).The decomposition and disintegration of solid wastes produce bad smells that pollute the surrounding air.

(ii). Different types of germs of diseases are produced where solid waste accumulate for long time. This condition causes dangers to the community health.

(iii). Decomposition of wastes lead to formation of many poisonous substances that join surface run off and cause serious water pollution.

• Disposal or Management of Solid Waste

Following are the methods through which wastes are disposed –

(1)Composting

(2)Land filling

(3)Thermal Process

(4)Recycling and Re-use

• Composting

Compost is natural manure. It is prepared by scientific decomposition of solid waste. For this, cemented and properly plastered pits of proper length and breadth are used. Following are the steps of compost preparation-

(i)Pits of 1meter wide, 1meter deep and as per the required length are dug and plastered from inside.

(ii). Biodegradable solid wastes are segregated out and broken down in small pieces by hammer.

(iii).Now biodegradable wastes are mixed with dung and leaves and filled into the pit.

(iv). A thin layer of soil is spread over.

(v).The filled in pit is watered properly once in a week so as to retain a minimum of 50% moisture.

It takes one to 6 months in preparing good compost. It takes only 3 to 7 days in preparing compost on commercial level because mechanical methods are used in it. In India about 410 million tones of compost is prepared every year.

(2) Land filling

In this method solid waste are filled in trenches and pits. After that wastes are pressed by roller. A layer of soil is spread over and again pressed by roller. Though this method is easy it may cause danger of soil pollution.

(3)Thermal Process

In this process solid wastes are burnt inside specifically made incinerators. This method is not preferred as it may cause air pollution.

(4) Recycling and Re-use

Making useful things by processing solid wastes is called as recycling. Solid wastes contain many useful things that can be re-used. Bottles and cans can be two of such things. Polythene can be used in making cushions and mats. Metal scraps, glass, plastics and iron can be segregated and sold. These substances are carried to factories where these are melted to make useful things.

Recycling and re-use are good methods of disposal of solid waste because –

• The problem of disposal of solid waste is solved through these processes
• These methods check wastage of resources.
• Through these processes objects on fewer prices can be made available.
• These methods can generate employment.